Tubular link construction



4 s. RITTER 2,457,275

TUBULAR LINK CONSTRUCTION I Filed April 16, 1946 ,Amm

.tracted relation by a spring 4|.

3 transverse cross section when formed from the blank as shown in Figs.7 and 8.

The ends 25 and side walls 22 and 24 extend to provide a pair of earshaving bearing apertures to receive a pintle 21 thereby providing ahinge connection in cooperation with apertured ears 28 and 29 of theinner tubular member H; of adjacent link assembly M.

The inner tubular member has a top wall 33, bottomwall 34 and sidewalls35 and 36. The member I6 is, as above pointed out so shaped anddimensioned as to slidably fit the outer member l providing thetelescopic assembly arranged to expand and contract producing anexpansible band when the link assemblies are hingedly connected.

For the purpose of holdingthe tubular members or sections in operativerelation the side walls of the inner member I 6 are provided withchannels 31 to receive lugs 38 formed on the side walls of the outermember IS. The channels are terminated at one end by a wall 39 to limitthe outward movement of the inner member 16.

The tubular members are held in normal con- One end of the spring may,as shown, be attached to a hook element 42 integral with the bottom wallof the tubular member [5. The opposite end of the spring 4| may, asshown, be attached to a hook element 43 integral with the bottom wall oftubular member IS. The spring 4| which is normally contracted holds thetubular members in contracted relation.

j An expansible band of the present character is sold in greatquantities and although of relatively intricate and complicatedconstruction, it must be manufactured at relatively low cost. It hasbeen found desirable from a practical standpoint, in meeting the demandsof high speed production to form each of the tubular members from sheetmetal blank so fabricated that a seam extends longitudinally of thebottom wall of each tubular member. As for example, the seam 44 formedin the bottom wall of memher [5 and the seam 45 in the bottom wall ofthe memb'er l6.

As shown in Figs. 2 to 4, when the members l5 and iii are in theirextended or expanded positions the member 'l6 is disposed with its end46 extending arelatively short distance into( member [5. When in thisexpanded position the member It acts as a lever and any lateral force asindicated by arrow :c, Fig. 3, applied to the member [6, as for example,at the hinge connection 41, serves to exert an amplified force to a sidewall of the member IS. A repetition of the application of this forcecauses a separation of the edges 48 and 49 of the seam 44. For thepurpose of preventing an opening of the seam 44 the edge 48 thereof isprovided with an extension 51 to be received in a complimentary notch 52formed in edge 49. This extension and notch maybe of any suitableinterlocking construction, as for example, a so-called dovetail joint.This joint or look is disposed relatively close to an end ofv member [5so as to lie beneath the end 46 ofa member l6 when extended. By reason"of this interlocking construction edges 48 and 49 are maintained incontacting relation and resist separation due toforce applied by lateralstresses'imparted to member i6 when in its extended position.

The locking means shown and disclosed lends itself to high speedfabrication of the links in that-the blanks may be punched with thecooperating locking formation and may be auto matically shaped to therequired tubular formation bringing the edges of the blank automaticallyinto interlocking relation by a single operation.

An expansible band of the type above described may be subjected tosevere and continuous use without distortion and provides a more durableand practical article as desired in this class of merchandise.

Although a preferred embodiment of the invention is shown and describedherein, it will be understood that modifications may be made thereinwithout departing from the spirit and scope of the invention as setforth in the appended claims.

What is claimed is:

I. An expansible band comprising a plurality of telescopical links, eachof said links including an outer member and an inner member, said innermember disposed in said outer member so as to be slidable from aposition wherein it is substantially fully received within the outermember to a position wherein a major portion of said inner memberextends from one end of said outer member, said outer member beingformed from a sheet metal blank to tubular form with the opposite edgesof the blank forming a longitudinal seam in a wall of said outer member,an extension adjacent to said end of said outer member and integral withone of said edges, said other edge having an aperture to receive saidextension to interlock said edges.

2. An expansible band comprising a plurality of telescopical links eachof said links including an outer and an inner member, the outer memberbeing formed from a sheet metal blank to tubular form with oppositeedges of the blank forming a longitudinal seam in the bottom wall ofsaid outer member, one end of said outer member having registeredapertures in side walls thereof, a hinge pin disposed in said aperturesto pivotally connect said outer member to an inner member and serving tohold the edges of the seam at one end thereof against separation andmeans alon the seam for interlocking the edges thereof againstseparation at the other end thereof.

'3. An expansible band comprising a plurality of telescopical links eachof said links including an outer and an inner tubular member, the outermember being formed from a sheet metal blank with opposite edges of theblank forming a longitudinal seam in the bottom wall of said outermember, one end of said outer member having registered apertures in sidewalls thereof, a hinge pin disposed in said apertures to pivotallyconnect said outer member to an inner member and serving to hold theedges of the seam at one end thereof against separation, a projectionintegral with one edge of said seam and an aperture on the other edge ofsaid seam to receive said projection to interlock the seam againstseparation at the other end thereof.

4. A link unit for an expansible band comprising inner and outer tubularmembers disposed in telescopical relation, the outer member being formedfrom a sheet metal blank with opposite edges of the blank forming alongitudinal seam in the bottom Wall of said outer member, one end ofsaid outer member having registered apertures in side walls thereof toreceive a hinge pin for pivotally connecting one end of an inner memberto said end of said outer member and thereby serving to hold the edgesof said seam atone end thereof against separation and means along theseam for interlocking the edges thereof against separation at the otherend thereof.

5. A link unit for an expansible band comprising inner and outer tubularmembers disposed in telesc opical relation, the outer member beingformed from a sheet metal blank to tubular form with opposite edges ofthe blank forming a longitudinal seam in the bottom wall of said outermember, one end of said outer member having registered apertures in sidewalls thereof to receive a hinge pin for pivotally connecting one end ofan inner member to said end of said outer member and to hold the edgesof said seam at one end thereof against separation and a projection toprovide a tenon integral with one of said edges,

6 the other of said edges having an indenture to receive said tenon andinterlock the edges of said seam against separation at the other endthereof.

SAUL RITTER.

REFERENCES CITED The following references are of record in the file ofthis patent:

Flaig Dec. 30, 1947

